dev-npgsql/npgsql: Npgsql is the .NET data provider for PostgreSQL.

src/Npgsql/Internal/PgBufferedConverter.cs

53 строки2 KB

Shay Rojansky

Add [Experimental] to converter-related APIs (#5668)

12 апр 2024, 21:12

12 апр 2024, 21:124e5fb5a

using System;
using System.Diagnostics.CodeAnalysis;
using System.Threading;
using System.Threading.Tasks;

namespace Npgsql.Internal;

[Experimental(NpgsqlDiagnostics.ConvertersExperimental)]
public abstract class PgBufferedConverter<T> : PgConverter<T>
{
    protected PgBufferedConverter(bool customDbNullPredicate = false) : base(customDbNullPredicate) { }

    protected abstract T ReadCore(PgReader reader);
    protected abstract void WriteCore(PgWriter writer, T value);

    public override Size GetSize(SizeContext context, T value, ref object? writeState)
        => throw new NotSupportedException();

    public sealed override T Read(PgReader reader)
    {
        // We check IsAtStart first to speed up primitive reads.
        if (!reader.IsAtStart && reader.ShouldBufferCurrent())
            ThrowIORequired(reader.CurrentBufferRequirement);

        return ReadCore(reader);
    }

    public sealed override ValueTask<T> ReadAsync(PgReader reader, CancellationToken cancellationToken = default)
        => new(Read(reader));

    internal sealed override ValueTask<object> ReadAsObject(bool async, PgReader reader, CancellationToken cancellationToken)
        => new(Read(reader)!);

    public sealed override void Write(PgWriter writer, T value)
    {
        if (!writer.BufferingWrite && writer.ShouldFlush(writer.CurrentBufferRequirement))
            ThrowIORequired(writer.CurrentBufferRequirement);

        WriteCore(writer, value);
    }

    public sealed override ValueTask WriteAsync(PgWriter writer, [DisallowNull] T value, CancellationToken cancellationToken = default)
    {
        Write(writer, value);
        return new();
    }

    internal sealed override ValueTask WriteAsObject(bool async, PgWriter writer, object value, CancellationToken cancellationToken)
    {
        Write(writer, (T)value);
        return new();
    }
}